Strong Anharmonicity-Induced Low Thermal Conductivity and High n-type Mobility in the Topological Insulator Bi Sb Te S.

Intrinsically low lattice thermal conductivity (κ ) while maintaining the high carrier mobility (μ) is of the utmost importance for thermoelectrics. Topological insulators (TI) can possess high μ due to the metallic surface states. TIs with heavy constituents and layered structure can give rise to high anharmonicity and are expected to show low κ .

Topological delocalization and tuning of surface channel separation in BiSeTe Topological Insulator Thin films.

The surface states of a 3D topological insulator (TI) exhibit topological protection against backscattering. However, the contribution of bulk electrons to the transport data is an impediment to the topological protection of surface states. We report the tuning of the chemical potential in the bulk in BiSeTe TI thin films, pinning it near the center of the bulk band gap, thereby suppressing the bulk carriers.